On the world's canaries

After her first book, Close to the Machine, was published in 1997 Ullman started to write more. The book, a "cult classic", was one of the first to really convey the appeal of code. But it's a curious mix – alongside the clear passion for the problem solving and possibilities is Ullman's unease at how much it could change our lives. She would build programmes for clients, who would then ask her how they could keep track of their employees' keystrokes, or databases that would also give government agencies access to private health information. Even just the way computers would...